Watchmaker&#39;s tool for adjusting balance-wheels.



. L. KOHN.

WATCHMAKERS TOOL FOR ADJUSTING BALANCE WHEELS. APPLICATION men APR. 15.1915.

1,153,695. Patented Sept. 14, 1915.

FTQE.

LoUIsKonn, or onroneo, ILLINOIS.

, Specification of Letters Patent.

Patented Sept. 14:, 1915.

Application filed. April 15, 1915. Serial No. 21,624.

' To all whom it may concern:

Be it known that I, LOUIS KoHN, a citi zen of the United States,residing at Chicago, in the county of Cook and State of Illinois, haveinvented new and useful Improvements in Watchmakers Tools for AdjustingBalance-ll heels, of which the fol lowing is a full, clear, concise, andexact description, reference being had to the accompanying drawing,forming a part of this specification.

My invention relates to improvements in indicating means for mechanismused in the adjustment of balance wheels, and has for its object theproduction of a device whereby any irregularity in the balance wheel maybe clearly indicated.

A. further object is the production of a device which may bereadilyattachedito the ordinary watch-makers calipers, whereby any irregularityin the balance wheel occasioned either by warping or bending or anydeviation from' the circular shape, may be readily detected andmeasured. 7

A further object is the production of a device by the use of which thebalance wheel may be quickly straightened and trued, without thenecessity of removing the balance wheel from the calipers.

A further object is the production of a cheap and efficient device, ofsimple construction, and one that is not liableto disarrangement ofparts. 7

These and such other objects as may hereinafter appear are attained bymy device, an embodiment of which is illustrated in the accompanyingdrawings, in which- Figure 1 represents a plan view of my de vice,inplace on a pair of watch-makers calipers; Fig.2 is a sectional. viewon line 22 of Fig. 1, looking in the direction indicated by arrows; Fig.3 is a sectional view on line 33 of Fig. 1, looking in the directionindicated by arrows; Fig. 4: is a sectionel View on line 44 of Fig. 2,looking in the direction indicated by arrows; and Fig. 5 is aperspective view of my improved guide and needle.

Like numerals of reference indicate like parts in the several figures ofthe drawing.

Referring by numeral to the accompanying drawings, 6 represents a pairof watchmakers calipers terminating in binding posts 7-7 and 88; 9 is abalance wheel in position to be operated upon, shown in dotted position.

My improved indicator comprises a plate 10 preferably having a cover orhood 11 cut away at 12 to expose the scale 13 on the plate 10. Rivetedto this plate at 14, and preferably integral therewith, is a back piece15 extending at right angles to the plate for a short distance, and thenparallel thereto. Said parallel portion 16 (best shown in Fig. 4) isprovided with a slot 17, the purpose of which will be shown later.Pivotally secured to the top of said plate, is an indicating needle 18,and seated on the same pivot and secured to the needle is a guide 19.This guide is preferably of a triangular cross-section, and terminatesat its lower edge in a knife edge 20. This guide is rigidly secured tothe needle, and when not held upwardly by reason of resting on thebalance wheel, drops forward, forcing the needle 18 against theright-hand side of the hood. In order to hold the needle and indicatingplate securely in place on the calipers, I provide a grip yoke 21comprising a flat portion adapted to rest against the base of thecaliper arm, and a pair of flanges 22 adapted to grip the arm. Securedto base of this yoke is a threaded bolt 23 passing through a thumb-nut24. This thumb-nut is provided with an enlarged portion 25 forming aseat 26 adapted to rest on the sides of the slot 17. A spring 27surrounds this bolt, pressing against the sides 16 of the slot 17 andthe bottom of the yoke 21. A spring 28 is preferably used to hold theneedle and guide in position against the side of the hood. The bindingposts 7 are provided with sockets 29 adapted to receive the axis of thebalance wheel 9 under adjustment.

The operation of my device is as follows: WVhen a balance wheel is outof true, either with respect to its horizontal plane or with respect toits circular form, the guide 19 is raised out of the way and the balancewheel 9 put in position between the binding posts of the caliper. Theknife-edge 20 of the guide then rests on the side of the balance wheeland the pointer 18 registers on the scale 13 say at zero. It is evidentthat the pointer need not necessarily register at zero, but at any pointon the scale, depending on the contour of the surface of the balancewheel. In Fig. 1 it is shown registered at zero. It is evident,therefore, that if the balance wheel is exactly true horizontally, andis revolved about its pivot points in the binding posts 7, the indicatorwill still point to zero during the entire revolution of the' wheel,excepting, of course, at the times when the knife-edge enters the spacesbetween the separate portions of the balance wheel. If, however, thewheel is at all out of true, the moment such portion of the wheel isbrought in contact with the knifeedge 20 of the guide, the indicatorwill move away from the zero or point indicated at the commencement ofthe operation. The operator then, by using his pliers, can straightenthe wheel without removing it from its pivot in the calipers. Thisoperation can be continued until the wheel is perfectly true and theindicator remains at the same point at the scale during the entirerevolution of the wheel. WVhen this opera tion is completed, thethumb-nut 24 is loosened, and the device turned through an angle ofpractically ninety degrees, so that the point 29 of the knife-edge 20engages the inner periphery of the wheel 9. The position of the needleis again noted on the scale, and the wheel then revolved. 'Any departurefrom a circle is clearly indicated on the scale, and the wheel truedaccordingly.

This device is of a simple construction,

and not at all liable to disarrangement of parts. It can readily beslipped over any calipers.

In the device illustrated, the yoke 21 is made rigid. Consequently itcan only pass over a certain portion of the caliper arm. The space,however, between the flanges is Copies of this patent may be obtainedfor five cents each, by addressing the Commissioner of Patents.

the shank .of the pointer. U

Having thus. described my.invention what scribed my name.

made large enoughso that a suflicient portion of the caliper arms may betraversed to bring the guide in proper position to contact with thebalance wheel under the operation.

It is evident, however, that r if occasion should arise, the yoke can bemade adjustable so it could fitover the larger portions of the arm orarms of large calipers if desired. Such a modification of the yoke canbe made without departing from the spirit device. It is also evidentthat the needle or pointer 18 and guide 19 may be formed of one piece,the gulde being a continuation-of I claim as new and desire to secure byLet ters Patent is; 1 V q An indicating device comprising a plate with aknife edge pivotally secured thereto, a pointer adapted to registerthemovements of said guidaand spring-pressed adjusting meansincludinggripping flanges whereby said plate may be secured in anydesired position on the arm of a pair of calipers.

In witness whereof, I have hereunto suborns KOHN.

Washington, D. 0.

having ascale thereon, a guide provided; r

